Application notes DERATING OF CONTACTS FOR DC VOLTAGES To establish a standard for the derating of relay contacts is, at best, a subjective practice. Limitations are governed by the type of relay, contact gap, maximum voltage capabilities of the relay ...

... Change in coil resistance due to change of ambient temperature can be calculated by the following formula. "Rule of Thumb" : For each 10°C change of temperature, coil resistance will change approximately 4%. 2. High and low temperature pick up voltage Date of issue: 6/00 RELAYS AND TEMPERATURE VARIATIONS Operating Current Voltage DOWN UP ...

Application notes The inductive nature of relay coils allows them to create magnetic forces which are converted to mechanical movements to operate contact systems. When voltage is applied to a coil, the resulting current generates a magnetic flux, creating mechanical ...

Types of suppressors: Passive devices. The resistor capacitor circuit It eliminates the power dissipation problem, as well as fast voltage rises. With a proper match between coil and resistor, approximate capacitance value can be calculated from 0.02xT/R, where ...

... At the opening time the current becomes constant as a result of practically zero opening speed. Due to this kind of behavior, this type of suppression must be avoided for power relays. For small relays which have to switch low currents of less than 0.2 A, degradation of life is not that significant and the method may be acceptable. ...

The diode + resistor network It eliminates the inconvenience of the resistor alone, explained above, and it limits the action of a single diode now preferred to used the diode + zener network. The diode + zener network ...